Dispensing freezer with control means



Jan. 11, 1966 H. F. SWENSON DISPENSING FREEZER WITH CONTROL MEANS 2 Sheets-Sheet 1 Filed Dec. 15, 1965 HARVEY F. SWENSON 4 INVENTOR.

ATTORNEYS Jan. 11, 1966 H. F. SWENSON DISPENSING FREEZER WITH CONTROL MEANS 2 Sheets-Sheet 2 Filed Dec. 13, 1963 HARVEY F. SWENSON INVENTOR.

ATTORNEYS United States Patent 3,228,2fi3 DISPENSTNG FREEZER WTTH CGNTROL MEANS Harvey F. Swenson, 3401 17th Ave. W., Seattle, Wash. Filed Dec. 13, 1963, Ser. No. 330,274 4 Claims. (Cl. 62-435) The present invention relates to improvements in dispensing freezers for ice cream, milk shakes, etc., of the type having a self-contained refrigeration system for its freezing cylinder, a miX-and-air feed system for automatically replenishing the freezing cylinder, a drive system for the dasher in the freezing cylinder, and an electrical control system.

This invention aims to provide improvements in the dasher drive system and electrical control system, improved cooling of the compressor in the refrigeration system, and an improved overall arrangement of the dispensing freezer components, making it possible to provide an unusually compact, efficient, and economical dispensing freezer which is easy to operate and requires a minimum of maintenance.

Other more particular objects and advantages of the invention, will, with the foregoing, appear and be understood in the course of the following description and clams, the invention consisting in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

FIG. 1 is a front perspective view of a dispensing freezer embodying the present invention;

FIG. 2 is a vertical sectional view taken on the line 22 of FIG. 1;

FIG. 3 is a vertical sectional view taken as indicated by line 3-3 of FIG. 2;

FIG. 4 is a detail elevational view of the idler shaft and related parts in the dasher drive system.

FIG. 5 is a schematic View of the refrigeration system; and

FIG. 6 is a schematic of the electrical control system.

Referring to the drawings it is seen that the dispensing freezer of the present invention has a frame 16 enclosed by a housing 17, and as viewed from the front is arranged with a freezing cylinder 13 at the right surmounted by a mix tank Zil, a dasher drive motor 21 at the left overlying a hermetically-sealed compressor 22 having a self-contained motor 22a, and a condenser 23 at the rear behind the dasher drive motor.

The refrigeration for the freezing cylinder 18 is a capillary tube system in which refrigerant flow to the capillary tube 24 is controlled by a solenoid valve 25. Tracing the system and starting at the compressor 22, the refrigerant passes therefrom through line 26 to the condenser 23 and then back and forth between the condenser and compressor through an oil cooling circuit 2728. The refrigerant then discharges from the condenser through a liquid line 30 containing a strainer 31 and the solenoid valve 25, and on through the capillary tube 24 into a flooded evaporator surrounding the freezing cylinder 18. From the evaporator the refrigerant passes through cooling coils 32 for the mix tank 20 via its return by line 33 to the compressor. It will also be noted that an accumulator 34 is provided in the return line 33 in heat eX- change relation to the capillary tube 24.

The freezing cylinder 18 and related evaporator, dasher, mix-and-air feeding system for the cylinder from the mix tank, and plunger serving gate 35 in the removable front cover for the cylinder, may be of the type described in U.S. Patent No. 2,924,951. It will be noted that the serving gate is operated manually by use of a handle 35a, and when lifted into dispensing position engages by its upper end the spring-urged actuating lever 36a of a normallyopen micro-switch 36, herein termed the serve switch.

Temperature of the freezing cylinder is sensed by a sensor bulb contained in a well 37 in the evaporator and controls the making and breaking of a double-pole single-throw temperature control switch unit 38.

Before describing the drive system from the motor 21 to the dasher in the freezing cylinder, attention is directed to the electrical control circuit. The manual control switch unit for the circuit is denoted 40 and may take the form of a four-position rotary switch, having an off position, a start position in which three contacts 40a, 40b and 400 are closed, a run position in which the contacts 40:: and 4% are closed and contact 400 is open, and a wash position in which only contact 460 is closed. Contacts 40:: and 40b are connected to the switches 38a and 38b of the temperature control switch unit 38, and contacts 40b and we are also selectively cross-connected by the serve switch 36. It will be noted that a lead 41 from the contact 400 by-passes the switch 3812. From the latter a lead 42 continues through a thermal overload 43 to the dasher motor 29.

The compressor motor 22a has its own thermal overload protector and conventional starting relay and capacitor arrangement, while the dasher motor 21 is equipped with an auxiliary centrifugal switch 44 with a back contact which self-closes as the motor builds up speed. Leads 454-5 connect the compressor motor 22a with the temperature control switch 38a and the centrifugal switch 44 thus making it impossible for the compressor to be operating unless the dasher is in operation. Power leads 47-48 connect with the control switch 4t and the dasher motor 21.

Of importance is the fact that the solenoid valve 25 is wired in parallel with the dasher motor 21 so that it always opens whenever frozen product is dispensed. To elaborate, the serve switch 36, by by-passing the temperature control switch 38, causes the dasher motor to operate whenever frozen product is dispensed. This raises the pressure at the suction side of the compressor and hence raises the refrigerant temperature at the temperature sensing well 37 much faster than would otherwise be the case. As a result the switches 38d-38b in the temperature control unit always close shortly after the dispensing operation is commenced thereby assuring matching operation of the compressor motor 22;; to give a quick freeze of the replenishing mix fed into the freezing cylinder responsive to the dispensing operation.

As before mentioned, contact 400 of the control switch unit closes when the latter is in its start and wash positions. This arrangement gives quicker starting of the dasher motor 21 and opening of the solenoid valve 25 at the beginning of a days operation than would be the case if such was initially dependent upon the temperature control 38, and makes it possible to stir cleaning solution in the freezing cylinder with the dasher at the close of the days operation without having the compressor running. The start position of the control switch 40 is used for only the first minute or 'so of operation, and then the switch is turned to the run position.

Continuing to the drive arrangement from the motor 21 to the dasher, the latter has a stub shaft 50 projecting from the rear of the freezing cylinder directly above a dead idler shaft 51. This shaft is kept in parallel relation to the dasher shaft 50 by a vertical guide plate 52 which is welded to the rear end thereof and depends into a vertical transverse pocket 53 at the back of the frame 16 of the freezer housing. This pocket 53 permits the guide plate 52 to move vertically or laterally relative to the frame 16 but restricts it against fore and aft movement. Thus the idler shaft 51 is free to move in any manner perpendicular to its own longitudinal axis, and at the same time is kept horizontal and is held against movement endwise of its longitudinal axis.

The motor 21 is bolted onto a shelf 16a above the compressor 22 with its output shaft 21a projecting rearwardly in parallel relation to the shafts 5051 and ,at about the same level as the former. A two stage speed reduction is accomplished from the motor to the dasher by a V-belt 54 sloping downwardly to the right from a drive pulley 55 on the motor shaft 21a to a larger idler pulley 56, and by a V-belt 57 extending upwardly from a reduced idler pulley 58 to a larger driven pulley 60 on the dasher shaft 50. The idler pulleys 56 and 58 are fixed to rotate together on a sleeve 61 which is in turn journaled on the dead idler shaft 51 and is held as by snap rings against longitudinal movement relative to the shaft. Tensioning of the belts 54 and 57 is accomplished by a pair of tension springs 62-63 which are anchored at their lower ends to the base of the frame 16. At its upper end the spring 62 hooks over the forward end of the idler shaft While the upper end of the spring 63 hooks through the eye of a pierced ear 64 welded to the idler shaft to the rear of the pulley 56. If desired, provision can be made between the lower ends of the springs 62-63 and the frame 16 for adjusting the spring tensions.

By the above described drive arrangement the idler shaft 51 floats in parallel relation to the motor shaft 21a and dasher shaft 50. The springs 62-63 are so positioned axially of the idler shaft relative to the idler pulleys 56 and 58 as to substantially balance the torque load on the shaft. Any unbalance is resisted by action of the guide plate 52 working in the pocket 53.

As previously indicated, the dasher drive motor 21 overlies the compressor 22 and is directly in front of the condenser 23, the back of which is exposed to the atmosphere. To force air through the condenser a fan 65 is provided having its hub fixed on the free end of the output shaft 21a of the motor 21 rearwardly of the drive pulley 55. Air intake for this fan is established at the front of the freezer housing 17 by louvers 66 located directly in front of the compressor 22 so that the flow path of the air will pass over the compressor. By this arrangement the compressor is cooled by the same air that is circulated by the fan through the condenser 22 and out the back of the housing. It is preferred that the housing 17 be otherwise closed so that the flow of incoming air therethrough will be concentrated around the compressor unit 22.

It is believed that the invention will have been clearly understood from the foregoing detailed description of my now-preferred illustrated embodiments. Changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly my intention that no limitations be implied and that the hereto annexed claims be given the broadest interpretation to which the employed language fairly admits.

I claim:

1. In a dispensing freezer, a frame, a dasher shaft and power-driven shaft carried by said frame and journalmounted in parallel spaced relation to one another, the axes of rotation of said shafts being fixed relative to one another, an idler shaft floating in spaced parallel relation to said power-driven and dasher shafts, belt-andpulley drive means from said power-driven shaft to said idler shaft to said dasher shaft, spring means anchored to said frame and acting on said idler shaft to yieldingly urge the idler shaft away from said power-driven and dasher shafts, and flat guide means projecting laterally from said idler shaft and fitting within a planar pocket on said frame wider than said guide means for holding the idler shaft parallel to said power-driven and dasher shafts while permitting the idler shaft to float laterally.

2. In a dispensing freezer, a frame, a freezing cylinder with a dasher therein having a rearwardly projecting dasher shaft, a motor spaced to one side of said cylinder and having a rearwardly projecting drive shaft, the axes of rotation of said shafts being fixed relative to one another, an idler shaft floating beneath said dasher shaft, cooperating guide means on said idler shaft and frame for holding the idler shaft in parallel relation to said drive and dasher shafts while permitting the idler shaft to float at right angles to its longitudinal axis, tension spring means anchored to said frame and pulling downwardly on said idler shaft at two points spaced apart longitudinally of its length, and flexible speed-reduction drive means from said drive shaft to said idler shaft between said two points and thence to said dasher shaft.

3. In combination, a dispensing freezer having a freezing cylinder with a discharge gate and a refrigeration system including a compressor and a solenoid valve for controlling the flow of refrigerant, a dasher in said freez ing cylinder, a motor for said compressor, a second motor for driving said dasher, and an electrical control system for said compressor motor, second motor and solenoid valve including a pair of normally-open switches closing responsive to an upper temperature limit of said freezing cylinder, said second motor being electrically connected to one of said pair of switches and having a normally-open centrifugal switch closed responsive to operation of said second motor, a circuit from the other of said pair of switches to said compressor motor and thence to said centrifugal switch, a circuit for said solenoid valve in parallel with said second motor, and an electrical power source having one of its poles connected to said pair of switches and its other pole connected to said centrifugal switch, second motor and solenoid valve, and a normally-open serve switch from the first-mentioned of said poles by-passing the first-mentioned of said pair of switches and arranged to be closed responsive to opening of said discharge gate.

4. The combination of claim 3, in which a wash switch is connected to the first-mentioned of said poles and also by-passes the first-mentioned of said pair of switches.

References Cited by the Examiner UNITED STATES PATENTS 916,721 3/ 1909 Kramer 74-2429 1,954,518 4/1934 Downer. 2,280,434 4/1942 Huber. 2,737,024 3/ 1956 Swenson 62--342 X 2,743,679 5/1956 Lofton 74221 X 2,930,203 3/1960 Koch 62342 X 3,145,575 8/1964 Bellmann 74228 ROBERT A. OLEARY, Primary Examiner. 

1. IN A DISPENSING FREEZER, A FRAME, A DASHER SHAFT AND POWER-DRIVEN SHAFT CARRIED BY SAID FRAME AND JOURNALMOUNTED IN PARALLEL SPACED RELATION TO ONE ANOTHER, THE AXES OF ROTATION OF SAID SHAFTS BEING FIXED RELATIVE TO ONE ANOTHER, AN IDLER SHAFT FLOATING IN SPACED PARALLEL RELATION TO SAID POWER-DRIVEN AND DASHER SHAFT, BELT-ANDPULLEY DRIVE MEANS FROM SAID POWER-DRIVEN SHAFT TO SAID IDLER SHAFT TO SAID DASHER SHAFT, SPRING MEANS ANCHORED TO SAID FRAME AND ACTING ON SAID IDLER SHAFT TO YIELDINGLY URGE THE IDLER SHAFT AWAY FROM SAID POWER-DRIVEN AND DASHER SHAFTS, AND FLAT GUIDE MEANS PROJECTING LATERALLY FROM SAID IDLER SHAFT AND FITTING WITHIN A PLANAR POCKET ON SAID FRAME WIDER THAN SAID GUIDE MEANS FOR DASHER THE IDLER SHAFT PARALLEL TO SAID POWER-DRIVEN AND DASHER SHAFTS WHILE PERMITTING THE IDLER SHAFT TO FLOAT LATERALLY. 